Pressure responsive safety switch



May 15-, 1951 c. STEIDER PRESSURE RESPONSIVE SAFETY SWITCH Filed Dec. 16, 1949 [III Clarence Steider INVENTOR.

Patented May 15, 1951 .UNITED STATES PATENT OFFICE PRESSURE RESPONSIVE SAFETY SWITCH Clarence Steider, Bruning, Nebr.

Application December 16, 1949, Serial No. 133,262

2 Claims.

This invention relates to improvements in an electrical switch mechanism, and more particularly to a pressure responsive safety switch for use as a safety device for ice machines, hot water heaters or the like.

An object of the invention is to provide means for selectively closing a pair of electrical contacts in accordance with pressure in fluid conduits to thus announce the existence of an undesirably low pressure or the presence of a broken diaphragm in the pressure responsive switch.

A further object of the invention is the provision of a pressure responsive switch which has means for predetermining the pressure at which a mercury switch will be tilted to such an angle that an electrical circuit will be formed between two opposed contacts.

Still further objects of the invention reside in the provision of a pressure responsive safety switch that is strong, durable, highly efl'icient in operation, simple in construction and design, capable of being readily disassembled for easy and convenient repair and service, relatively easy to manufacture, and quite inexpensive.

. These, together with various ancillary objects and features of the invention which will become apparent as the following description proceeds, are attained by this pressure responsive safety switch, a preferred embodiment of which has been'illustrated in the accompanying drawings,

for way of example only, wherein:

Figure l is a top plan view of the invention shown in a position with the mercury switch in a close circuit position; Figure 2 is a vertical sectional view of the pressure responsive safety switch which shows in greatest detail the cooperation of the various elements thereof; and

Figure 3 is a vertical sectional view as taken along the line 33 in Figure 2, and being enlarged to show the means for supporting the mercury switch in greatest detail.

With continuous reference to the accompanyin drawings wherein like reference numerals designate similar parts throughout the various views, reference numeral I is used to generally designate the safety switch comprising the present invention. This switch employs a pressure responsive diaphragm I2 between two portions of a casing I4 and I6 in which a shaft I8 secured to the diaphragm actuates a mercury switch to close an electrical circuit to an alarm or other signaling device of any desired characteristics.

As seen best in Figure 2, the diaphragm I2 is constructed of synthetic or natural rubber or of any other convenient and flexible waterproof material. Obviously, resilient plastics which are resistant to a chemical action of corrosive fluids is specifically desirable. The diaphragm I2 is secured between the sections I4 and I6 of the casing and is held therebetween by bolts 22 and nuts 24. The section I6 is formed with hollow cylindrical side walls 26 and a bottom wall 28 forming a fluid chamber 30 into which a threaded inlet openin 32 extends. Obviously, a nipple or other suitable conduit may be screwed into the inlet opening 32.

The upper section I4 of the casing is hollow and is internally threaded for reception of an externally threaded plug 34. The plug 34 is hollow for reception in a sliding manner of the shaft I8. The shaft is threaded at its lower end for reception of threaded washers 36 and 38, which hold the shaft in secure engagement with the diaphragm I2.

A sprin 40 concentric with the shaft I8 is placed thereabouts in such position as to bias the washer 36 and the plug 34. Obviously, as the plug 34 is screwed in further compression will be applied upon the spring 40. Thusly, a lock washer 42 is provided to maintain the plug 34 in a given position relative to the casing I4. A further bearing plug 44 is threaded into the plug 34 in order to provide better means for slidingly receiving the shaft I8.

Integrally formed or elsewlse secured to the section I4 of the casing is an upwardly extending post 46 which is formed with an aperture 48 therethrough. The shaft I8 is also provided with a hole 50. A substantially Z-shaped crank 52 is secured within the hole and a threaded rod 54 is journaled in the aperture 48. The rod 54 is provided with a head 56 which engages a bracket bar 58 in which the rod 54 is journaled. The crank 52 extends through another hole or opening through the bracket bar 58 for pivotal movement. Threaded nuts 68 are provided to hold the rod 54 in a secure manner. Secured to the bracket bar 58 is an open clamp 62 of conventional design through which bolt 64 extends for engagement with nut 66 for closing the clamp. The mercury switch 20 is encompassed by the clamp 62 in a rigid and secure manner.

When the diaphragm I2 is subjected to the presence of a fluid under pressure it will be displaced so as to pivotally rotate the mercury switch 20 by causing the upward movement of the shaft I8 so as to cause the mercury in the switch 20 to close an electrical circuit between opposed contacts connected to lead wires 68 and 10. However, when the pressure on the diaphragm I2 is too greatly reduced, the shaft 18 will descend and the switch 20 will rotate to such position that the mercury will open the circuit between the contacts and the switch 28, Thusly, when this device is used as a safety switch on an ice machine or a hot water heater or other kind of electrically operated water-cooled unit, when the water under pressure from the pump is substantially reduced or the pressure of the water from the pump is reduced the operating switch to the machine may be opened to thus prevent destruction of the machine due to the lack of cooling fluid. When the water pressure gets up to normal it will close the operating switch and start the machine again.

Since from the foregoing, the construction and advantages of this pressure regulator safety switch are readily apparent, further description is believed to be unnecessary.

However, since numerous modifications will readily occur to those skilled in the art from a consideration of the foregoing specification and accompanying drawings, it is not intended to limit the invention to the precise embodiment shown and described, but all suitable modifications and equivalents of this safety switch may be readily resorted to which fall within the scope of the appended claims.

Having described the invention, what is claimed as new is:

1. A switching mechanism comprising an internally threaded casing, a plug threadedly engaged in said casing, a shaft slidably mounted in said plug and extending therethrough, a, pressure responsive diaphragm secured in said casing, said shaft being secured to said diaphragm, resilient means biasing said plug and said diaphragm, the position of said plug being adjustable to preset an initial compression on said resilient means, lock means selectively engaging said plug and said casing for locking said plug relative to said casing to retain the initial compression on said resilient means, an aperture in said casing, a hole through said shaft, a rod journaled in said casing in said aperture, a crank secured to said shaft in said hole, said rod and said crank being journaled in a bracket bar, clamp means secured to said bracket bar, and electrical contact making and breaking means secured to said clamp means. v

2. A switching mechanism comprising an internally threaded casing, a plug threadedly engaged in said casing, a shaft slidably mounted in said plug and extending therethrough, a pressure responsive diaphragm secured in said casing, said shaft being secured to said diaphragm, resilient means biasing said plug and said diaphragm, the position of said plug being adjustable to preset an initial compression on said resilient means, lock means selectively engaging said plug and said casing for locking said plug relative to said casing, an aperture in said casing, a hole through said shaft, a rod journaled in said casing in said aperture, a substantially Z- shaped crank secured to said shaft in said hole, said rod and said crank being journaled in a bracket bar, and clamp means secured to said bracket bar, said clamp means rigidly holding a mercury switch.

CLARENCE STEIDER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

